Pseudohalogens
Pseudohalogens are a special case of pseudo elements . The pseudohalogens include the following groups:
- -CN, -N 3 , -OCN, -NCO, -CNO, -SCN, -NCS, -SeCN
The chemical properties of these pseudohalogens are similar to those of the halogens in many areas :
- Analogous to the elementary halogens, there are mostly dimers of the pseudohalogens, for example dicyan (NC – CN).
- There are pseudo-halogenic acids of the type HX (with X as the pseudohalide):
- HCN ( hydrocyanic acid )
- HNCO ( isocyanic acid )
- HCNO ( acidic acid )
- HNCS ( isothiocyanic acid )
- HN 3 ( hydrazoic acid )
- HSeCN ( selenocyanic acid )
- The acids form metal salts of the type MX n (with a metal M). The salts AgX, Hg 2 X 2 and PbX 2 are, like those of the halides, sparingly soluble in water.
- Many metal cations form pseudohalogeno complexes with pseudohalides , e.g. B. of the form MX 4 n− or MX 6 m− .
- Covalent non-metal compounds such as P (CN) 3 are formed.
- The pseudohalogens form with one another and with the halogens compounds which correspond to the interhalogen compounds , e.g. B. ClCN , BrCN , ICN, XSCN, IN 3 .
- In alkaline solutions , disproportionation occurs with pseudohalogens .
literature
- Qualitative inorganic analysis, Eberhard Gerdes, 2nd, corrected edition, Springer Verlag